PREPARATION:1. Simmer corn with salt in the water, covered, 20 minutes, or until very tender.2. Purée soup in batches in a blender until very smooth (use caution when blending hot liquids). 3. As each batch is puréed, pour through a coarse sieve, pressing on solids, into a saucepan if serving hot or into a metal bowl if serving cold.4. Reheat soup, stirring, or chill it by setting bowl of soup in a larger bowl of ice and cold water and stirring. If soup is too thick, thin with water.